Subaru WRX STI
Subaru of America, Inc. introduced the all-new 2015 WRX STI, Subaru’s iconic performance flagship model, at the 2014 North American International AutoShow. Subaru will offer a WRX STI Launch Edition, limited to 1,000 units and exclusively featuring WR Blue paint and gold BBS® forged alloy wheels and unique interior trim.
Powered by the legendary 305-horsepower 2.5-liter turbocharged BOXER engine, the 2015 WRX STI debuts a new four-door wide-body design, built on a stiffer chassis for even greater handling agility and precision. The WRX STI provides a rally-bred drivetrain and all-wheel drive handling that is unique to this model. Handling is enhanced with a stiffer chassis, firmer springs and faster steering (13.0:1 ratio).
New for the 2015 WRX STI, Active Torque Vectoring joins an arsenal of the model’s proven handling technologies that includes Multi-Mode Driver Controlled Center Differential (DCCD) Symmetrical All-Wheel Drive, Multi-Mode Vehicle Dynamics Control, and a Brembo® Performance Brake System with Super Sport ABS.
The 2015 WRX STI carries its bold personality inside, where new Alcantara seating surfaces accented by red and black leather bolsters and red stitching set the tone for the upgraded and roomier cabin. A driver-focused interior remains integral to the WRX STI performance character, with the new model debuting a motorsports-inspired flat-bottom steering wheel and new whiplash-reducing performance-design front seats with height and tilt-adjustable head restraints. A wide array of new user technologies include, for the first time in a WRX STI, availability of a harman/kardon® premium audio system.
Iconic STI Design Exclusively in Sedan Form
A bolder front design makes the 2015 WRX STI look ready to devour the road. The “nose-cone” configuration combines the grille and bumper cap into one unit ahead of the hood, which for the 2015 model is made from aluminum to reduce weight over the front of the car. Narrower headlights, designed to evoke a raptor’s stare, flank the Subaru hexagonal grille. It’s a more powerful stare thanks to new standard LED low-beam headlights.
The special hood, fenders, doors and quarters, bumpers, headlights and taillight clusters convey the WRX STI identity. As on previous WRX STI models, a functional hood scoop supplies the intercooler with fresh air, and in the 2015 model it is set more deeply into the hood to provide better forward visibility.
Other new performance-oriented details include foglight surrounds with a carbon fiber-like pattern and front fender vents that feature a mesh screen. A full aerodynamic body package includes the large trunk spoiler that has been a WRX STI signature feature. A rear diffuser, LED taillights and LED center high-mount stop lamp (CHMSL) leave a distinctive signature.
New, Stiffer Chassis for Greater Handling Agility
The 2015 WRX STI body structure makes greater use of high-tensile steel than the previous model and features special stiffening elements at key locations. The stiffer chassis helps yield a super-quick steering response that was benchmarked against top-handling sports cars. The 13.0:1 steering ratio provides a quick 2.5 turns lock-to-lock compared to 14.5:1 and 2.8 for the standard WRX model.
As on previous WRX STI models, the 2015 version uses an exclusive inverted-strut front suspension system that provides higher levels of cornering agility. Aluminum front lower L-arms reduce unsprung vehicle weight. The STI-tuned suspension teams with standard 18-inch wheels and 245/40R18 summer performance tires, with the WRX STI Launch Edition and WRX STI Limited models featuring BBS® forged aluminum-alloy wheels.
305-hp Turbo BOXER Engine
The 2015 WRX STI is powered by a 2.5-liter turbocharged/intercooled 4-cylinder BOXER engine that employs the Dual Active Valve Control System (Dual AVCS). The engine, which is exclusive to the STI model, produces 305 horsepower (SAE) at 6,000 rpm and 290 lb.-ft. of peak torque at 4,000 rpm.
The WRX STI engine is teamed exclusively with a specially reinforced 6-speed manual transmission, which includes an STI short-throw shifter in the Launch Edition model. Incline Start Assist can momentarily prevent the car from rolling backward when being driven away from a stop on an incline.
The Subaru Intelligent Drive (SI-DRIVE) powertrain management system allows the driver to tailor the car’s driving characteristics by choosing from among three selectable modes – “Intelligent,” “Sport” and “Sport Sharp” – using a rotary dial on the center console. SI-DRIVE alters vehicle performance characteristics by regulating the engine control module and by fine-tuning the electronic throttle control system.
Multi-Mode DCCD All-Wheel Drive with Three-Mode Vehicle Dynamics Control
The 2015 WRX STI is exclusively equipped with the Multi-Mode Driver Controlled Center Differential (DCCD) version of Subaru Symmetrical All-Wheel Drive. This sophisticated system uses planetary-type center differential gears with a nominal 41:59 torque split. A mechanical limited-slip type center differential augments an electronically controlled center differential to enhance torque transfer performance.
Sensor inputs that include steering angle, throttle position, RPM, lateral-g, yaw, brake, ABS and wheel speed govern torque transfer response. A helical-type limited-slip front differential and a TORSEN® torque-sensing limited-slip rear differential optimize side-to-side torque distribution.
The DCCD AWD system features three automatic modes, each using varying degrees of center differential locking to match different driving situations. In manual mode, the driver can select one of six center differential locking levels to suit the driving situation.
Active Torque Vectoring, an enhancement of the Multi-Mode Vehicle Dynamics Control (VDC) stability and traction control system, can apply brake pressure to the inside front wheel to facilitate more neutral cornering. The VDC system offers yet more driver choices, with three settings: “VDC Normal,” “Traction” and “Off.” Each provides respectively lesser degrees of system engagement, allowing the driver to tailor response for the driving situation. Active Torque Vectoring remains engaged for “Normal” and “Traction” modes.
A one-inch longer wheelbase than the previous WRX STI helps provide a roomier cabin in the new model. The windshield is more raked than before, with the A-pillar pulled forward nearly eight inches at the base for better forward visibility, aided by a lower dashboard and narrower A-pillars. Lower side sills and wider-opening doors make ingress/egress easier. Rear seat legroom is increased by nearly two inches, and trunk capacity is now 12 cu. ft., up from 11.3 cu. ft. in the previous WRX STI sedan. A standard 60/40-split fold-down rear seat extends versatility. New available Welcome Lighting responds to the driver approaching the car.
In the 2015 WRX STI, the driver grips a new flat-bottom, leather-wrapped tilt/telescoping steering wheel that integrates switches for audio and Bluetooth control. The STI Design electroluminescent gauge panel gets a new 3.5-in. central LCD screen that displays various functions, including low-level warnings for oil and windshield washer fluid and the selected gear.
Rich-looking appointments and details abound, including soft-touch materials for the dashboard, door trim and center console armrest. A new multi-information central display with 4.3-in. LCD screen provides a multitude of vehicle system functions, including a standard rear camera display, a boost gauge display, audio (on non-navigation models), Bluetooth and climate control settings, and a VDC screen showing traction control operation. The display can also provide a vehicle self-check and maintenance reminder.
Standard features for the 2015 WRX STI include dual-zone automatic climate control and the All-Weather Package (dual-mode heated front seats, heated exterior mirrors and windshield wiper de-icer). The new standard audio system combines AM/FM stereo with HD Radio®, a single-disc in-dash CD player, 6 speakers, MP3/WMA capability, Radio Data Broadcast System (RDBS), Bluetooth hands-free calling and audio streaming, iPod® control capability, iTunes® Tagging, SiriusXM® Satellite Radio (subscription required), USB port and a 3.5mm auxiliary audio input jack. Numerous compartments located in and around the center console hold phones, USB drives and MP3 players.
An available touch-screen navigation system displays on a 6.1-inch LCD screen and offers voice controls. The WRX STI Limited model adds the luxury of leather-trimmed upholstery, an 8-way power driver’s seat, the harman/kardon premium audio system and a power moonroof that opens one inch farther than on the previous model.
Subaru’s renowned safety package uses the brand’s proven Ring-shaped Reinforcement Frame body structure, which has been shown to excel in the new small overlap test by the Insurance Institute for Highway Safety (IIHS). In the cabin, a driver’s knee airbag is added to the roster of safety features that includes front side pelvis/torso airbags and side curtain airbags that offer front and rear outboard seat coverage.
Subaru produces a full line of all-wheel drive sedans, crossovers and SUVs, along with the rear-wheel drive BRZ sports car.
Source: Subaru Press